• Wind and Structures
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• 제10권2호
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• pp.121-133
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• 2007

To gain understanding of the applicability of carbon fiber reinforced polymer (CFRP) cable in cable-supported bridges, based on the Runyang Bridge and Jinsha Bridge, a suspension bridge using CFRP cables and a cable-stayed bridge using CFRP stay cables are schemed, in which the cable's cross-sectional area is determined by the principle of equivalent axial stiffness. Numerical investigations on the dynamic behavior, aerostatic and aerodynamic stability of the two bridges are conducted by 3D nonlinear analysis, and the effect of different cable materials on the wind resistance is discussed. The results show that as CFRP cables are used in cable-supported bridges, (1) structural natural frequencies are all increased, and particularly great increase of the torsional frequency occurs for suspension bridges; (2) under the static wind action, structural deformation is increased, however its aerostatic stability is basically remained the same as that of the case with steel cables; (3) for suspension bridge, its aerodynamic stability is superior to that of the case with steel cables, but for cable-stayed bridge, it is basically the same as that of the case with steel stay cables. Therefore as far as the wind resistance is considered, the use of CFRP cables in cable-supported bridges is feasible, and the cable's cross-sectional area should be determined by the principle of equivalent axial stiffness.

• Structural Engineering and Mechanics
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• 제59권4호
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• pp.621-652
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• 2016

A new cable-supported bridge model consisting of suspension parts, self-anchored cable-stayed parts and earth-anchored cable-stayed parts is presented. The new bridge model can be used for suspension bridges, cable-stayed bridges, cable-stayed suspension bridges, and partially earth-anchored cable-stayed bridges by varying parameters. Based on the assumption that each structural member is in either an axial compressive or tensile state, and the stress in each member is equal to the allowable stress of the material, the material quantity for each component is calculated. By introducing the unit cost of each type of material, the estimation formula for the cost of the new bridge model is developed. Numerical examples show that the results from the estimation formula agree well with that from the real projects. The span limit of cable supported bridge depends on the span-to-height ratio and the density-to-strength ratio of cables. Finally, a parametric study is illustrated aiming at the relations between three key geometrical parameters and the cost of the bridge model. The optimization of the new bridge model indicates that the self-anchored cable-stayed part is always the dominant part with the consideration of either the lowest total cost or the lowest unit cost. It is advisable to combine all three mentioned structural parts in super long span cable supported bridges to achieve the most excellent economic performance.

• 한국지진공학회논문집
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• 제24권4호
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• pp.169-178
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• 2020

In a previous paper, ambient vibration tests were conducted on a cable stayed bridge with resilient-friction base isolation systems (R-FBI) to extract the dynamic characteristics of the bridge and compare the results with a seismic analysis model. In this paper, a nonlinear seismic analysis model was established for analysis of the bridge to compare the difference in seismic responses between nonlinear time history analysis and multi-mode spectral analysis methods in the seismic design phase of cable supported bridges. Through these studies, it was confirmed that the seismic design procedures of the "Korean Highway Bridge Design Code (Limit State Design) for Cable Supported Bridges" is not suitable for cable supported bridges installed with R-FBI. Therefore, to reflect the actual dynamic characteristics of the R-FBI installed on cable-supported bridges, an improved seismic design procedure is proposed that applies the seismic analysis method differently depending on the seismic isolation effect of the R-FBI for each seismic performance level.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.206-213
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• 2008

Mo-Am arch bridge is only the long-span bridge (with 125m span) in the Kyong-Bu high-speed line in service, while other bridges are PSC box girder bridges and steel composite bridges with span lengths of $25\sim50m$. However, in foreign high-speed lines, special cable-supported bridges like cable-stayed bridges and extradosed bridges are being adopted in earnest with technical specifications. The cable supported bridge is recognized as one of the indices of technology in civil engineering field, and thus it is being adpoted with a sense of rivalry in countries with advanced technology in railway engineering. In this paper, to apply the top-level cable-supported bridge technology to the domestic high-speed line up to 400km/h by establishing the technical specifications on cable-supported bridges including span length, the requirements for securing the dynamic stability and running safety of high speed train are analyzed through case studies for domestic and foreign cases.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 추계 학술발표회 논문집
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• pp.349-352
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• 2006

According to current bridge design code cable supported bridges are designed generally against 1000-year-return-period earthquake. Considering its importance, however, it may be desirable to design against 2400-year-return-period earthquake. But the seismic behavior of cable supported bridges under higher seismicity is not investigated fully. In this study, several cable supported bridges were analyzed under higher seismicity and then the response forces in prime members were compared with those analyzed under current design earthquake.

• 한국지진공학회논문집
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• 제24권4호
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• pp.157-167
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• 2020

In this study, a field bridge test was conducted to find the dynamic properties of cable supported bridges with resilient-friction base isolation systems (R-FBI). Various ambient vibration tests were performed to estimate dynamic properties of a test bridge using trucks in a non-transportation state before opening of the bridge and by ordinary traffic loadings about one year later after opening of the bridge. The dynamic properties found from the results of the tests were compared with an analysis model. From the result of the ambient vibration tests of the cable supported bridge with R-FBI, it was confirmed that the dynamic properties were sensitive to the stiffness of the R-FBI in the bridge, and the seismic analysis model of the test bridge using the effective stiffness of the R-FBI was insufficient for reflecting the dynamic behavior of the bridge. In the case of cable supported bridges, the seismic design must follow the "Korean Highway Bridge Design Code (Limit State Design) for Cable supported bridges." Therefore, in order to reflect the actual behavior characteristics of the R-FBI installed on cable-supported bridges, an improved seismic design procedure should be proposed.

• Interaction and multiscale mechanics
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• 제1권3호
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• pp.381-396
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• 2008

The aerostatic instability of cable-supported bridges is studied, with emphasis placed on modeling of the geometric nonlinear effects of various components of cable-supported bridges. Two-node catenary cable elements, which are more rational than truss elements, are adopted for simulating cables with large or small sags. Aerostatic loads are expressed in terms of the mean drag, lift and pitching moment coefficients. The geometric nonlinear analysis is performed with the dead loads and wind loads applied in two stages. The critical wind velocity for aerostatic instability is obtained as the condition when the pitching angle of the bridge deck becomes unbounded. Unlike those existing in the literature, each intermediate step of the incremental-iterative procedure is clearly given and interpreted. As such, the solutions obtained for the bridges are believed to be more rational than existing ones. Comparisons and discussions are given for the examples studied.

• 한국구조물진단유지관리공학회 논문집
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• 제22권5호
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• pp.1-12
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• 2018

이 연구는 2016년 발생한 경주 지진의 규모 4.5이상의 3개 지진, 즉, 전진(규모 5.1), 본진(규모 5.8), 여진(규모 4.5)에 대한 국내 공용 중 케이블교량의 지진응답 특성을 제시한다. 교량 주위의 자유장과 교량 내 지정된 위치에 설치된 지진가속도계측기에서 측정된 지진가속도응답기록을 이용하여 케이블교량의 각 구조부재별 지진응답을 분석한다. 측정 가속도 시간이력의 푸리에 변환을 이용한 주파수 영역 해석을 통하여 교량의 동적 거동 특성을 분석한다. 주탑 상부에서의 최대가속도를 자유장 위치에서의 최대가속도로 표준화하여 주탑 상부에서의 가속도 증폭에 대하여 분석한다. 분석 결과를 통해 지진 재난에 대응하기 위한 케이블지지교량의 지진가속도계측기 위치별 관리 기준치 개발의 필요성에 대해 논의한다.

• 한국방재안전학회논문집
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• 제15권4호
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• pp.31-38
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• 2022

케이블로 상부구조가 지지되는 특수교량의 경우 특수한 장비와 인력이 없이는 접근이 어려운 사각지대가 다수 존재하고 있어, 안전점검에 많은 애로사항이 발생하고 있는 것이 현실이다. 본 연구에서는 사장교와 현수교 등 케이블지지교량의 안전점검 사각지대를 검토하고, 드론을 활용하여 사각지대를 해소할 수 있는 방안을 연구하는 것이 목적이다. 이를 위해 해상에 위치한 사장교를 드론을 활용하여 케이블과 보강형 그리고 주탑을 점검하였다. 본 연구를 통해 드론을 활용하여 점검자의 접근이 어려운 특수교량의 외부 안전점검이 가능함을 확인하였다. 특히 특수교량의 점검사각지대인 주탑 외부 상태 및 손상 확인을 위한 드론 점검은 매우 효과적인 안전점검 방법이다.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2005년도 춘계 학술발표회 논문집
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• pp.265-272
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• 2005

For bridge-vehicle interaction analysis of cable-supported brides, the superposition method is applied based on the results of 3-dimensional free vibration analysis using General-purpose FEM Software. This study firstly performs the eigenvalue analysis for the free vertical and the torsional vibration of bridges using FEM analysis. Next the equations of motion considering interaction between bridges and vehicles/train are derived from mode superposition method. And then dynamic analysis is performed using the Newmark numericial method. Finally through the numerical examples, the dynamic responses of cable-supported bridges by this study are presented and discussed.